A. Field of the Invention
Concepts described herein relate generally to data prefetching, and more particularly, to optimizing prefetching over wide area networks (WANs).
B. Description of Related Art
Geographically distributed entities, such as a business with multiple local offices in different locations, frequently desire to maintain a logically unified proprietary network that is accessible by all of the geographically distributed entities. To accomplish this, a wide area network (WAN) may be used to link the different locations.
Information technology (IT) managers within geographically distributed entities face the conflicting requirements of keeping costs in check while providing users with new and faster applications. This conflict is most acute on the WAN, where costs can be high and getting applications to perform well is hampered by limited bandwidth and high latency.
Solutions are known to help improve performance over the WAN portion of a network. These solutions may be based on a number of technologies, including data compression, data caching, application-specific acceleration, policy-based bandwidth allocation, and data prefetching.
Data prefetching, in particular, may be used to reduce the perceived latency (response time) of data being accessed over a WAN. In general, the phrase data prefetching may include requesting and retrieving data in advance of an actual user or application-level request. One problem encountered when prefetching data is the determination of what data to prefetch, as well as when and how frequently to perform the prefetching operation. On one hand, prefetching unnecessary data may result in wasted resources, while prefetching too frequently results in decreased performance for system users.